Pull-chain terminal



June 12, 1928.

J. J. COOK PULL (EHAIN TERMINAL Filed June 5, 1927 INVENTOR J J 600K BY M (Q ATTORNEYS Patented June 12, 1928. I

UNITED, STATES semi J. 000:, or cnrcaeo, more FULL-CHAIN W113.

Application fled June 3,

-pull chain terminal which may be made at a minimum cost of light materialsuch as thin sheet brass, but which is so made that it is 20 strong enough to resist a compression strain or a tension strain.

A further. object is to provide a terminal which necessitates the use of relatively little material, thereby further decreasing the cost' of manufacture.

A further object isto provide a terminal having a slot for admitting the central wire portion of a ull chain, the terminal being so constructed hat when it is attached to the chain the slot will be closed, thus obviating the necessity of soldering or further steps in the making of the terminal.

Other objects and advantages will appear in the followin specification, and the novel features of the invention will be particularly pointed out in the appended claims.

My inventionis illustrated 1n the accompanying drawings, forming part of this application, in which Figure 1 is a side view of the device, showing one embodimentof the invention,

Figure 2 is an enlarged plan view,

Figure 3 is an enlarged side view, a portion being broken away,

Figure 4' is a bottom view,

Fi re 5 is a view showing an extension cord ing applied to the terminal, and

Figure 6 shows the osition of the terminal when the cord has 11 applied.

- In carrying out my invention, I make use, as stated, of a piece of thin metal, such as brass. This is stamped into the form shown. In the drawings, I have illustrated a hexagonal shape as being the preferred form, although other shapes might be used without departing from the invention. It will be observed that the device has abody portion 1 which is curved at its top, as shown at 2, and is provided with a central 0 ning 3.

rious parts of the device, the operation The top is corrugated to provide ridges 4 RElSSUEB- thereof may be readily understood. The main feature of the invention, as stated before, is to provide a terminal which can be I cheaply made but which will have a pleasing appearance and which will not crash under the ordinary force used in manipulating the electric switch, although the device is made of sheet metal which is relatively thin.

:The terminal is attached to the chain by slipping the central wire portion 7 of the chain into the slot 6. order to guide it into the slot, I preferably widen the latter slightly, as shown at 6' in Figure 3. One of the balls 8 of the chain is slipped; underneath the opening 3, where it is centered. Owin to the corrugations, the sides of the slot wifi spring together so that it will be virtually closed as shown in Figure 1, thereby obviating the necessity of any further steps in the manufacture. I have found that where these corrugations are not present, as for instance where the terminal is made of a smooth, hemispherical shell, there will not "be this spring action which tends to close the slot and that the slot will remain open. The corrugating of the terminal, therefore, has a double function. It makes 'ble the use of a very thin piece of meta in the making of a terminal which would otherwise be crushed out of shape and at the same time it provides aspring action, so that when the chain is in position, the slot willbe closed. Itis necessary that the axis of the corrugation's be substantially transverse to the direction of the slot. If, for instance, the corrugations were concentric with the opening 3, then the slot from the central opening to the edge would not close but would remain 0 en. The provision of the corrugations a prevents any possibility of the chain pulling out from the opening by the springing awe of the metal.

It will be seen that I have provided a terminal which can be made of very thin metal at one stamping o ration. The terminal is designed to take t e lace of the ball terminals which are difiicu t to make because they require a number of operations, thus increasing the cost.

Another useful feature connected with my improved terminal is that it may he used in connection with an extension cord by merely looping the cord over the terminal.- Thus in igure 5 I have shown the terminal as being reversed from the position shown in 110 I Figure 1; that is to say, the bottom ball of the hall chain is outside-instead of inside. lit is only necessary to loop the cord 9 over the upper end of the terminal and then pull it down so that the terminal will then as same the position shown in Figure 6 and the edge of the terminal next to the cord will keep it in position during use. Ordi- .narily, with terminals of other types, the

cords have to be tied to prevent disengage mentof the cord during use.

21A pull chain terminal, comprising a single piece of metal stamped into hell shape and having corrugations extending from a point near the center of the closed end toward the edge of the bell shaped piece, said closed end having a central opening, and a slot extending from said central opening to the edge of the terminal, the longitudinal axis of the slot being at right angles to the axis of the adjacent corrugations.

3. A pull chain terminal comprising a single piece of relatively thin metal stamped into hell shape and having radially extending ridges and grooves on its closed end, said terminal being adapted'to be reversed upon the pull chain, said closed end having a central opening and a slot from said central opening to the edge of the terminal.

. JOHN J. COOK. 

